Conveyor systems for transporting discrete goods between upper and lower conveyor bodies are used in the prior art in connection with labeling and control as well as tracking goods. For example, such conveyor systems may be used to transport packages containing pharmaceutical products, packaged foods, or other products that have or are to obtain one or more labels and/or whose labeling is to be detected for control purposes. Such labeling and inspection devices are preferably arranged very close to each other, so as to occupy little space in production plants. Conveyor systems may also be used in connection with serialization and aggregation of individual packages into bundles or containers, for which the individual packages (or groups of packages formed from them) are to be checked or processed with regard to their labels or other properties.
In order to handle goods having different properties (shape/geometry, material, color, weight, etc.) in a modern fully automated production or inspection plant, such plants must have high flexibility. Since the goods (also sometimes referred to as “products” in the following) must preferably be moved through the plants at high speeds (for example, 1 to 4 m/sec), the adjustment and changeover for handling goods with different properties must take place rapidly and error free.
Conveyor units having a lower and an upper conveyor belt are known for handling goods of different properties. A good to be processed is transported in such a conveyor unit between the lower and upper conveyor belts, either lying only on the lower conveyor belt or being clamped at the same time by the upper conveyor belt. In clamped state the goods can move accurately in time and position, so that, for example, a label provided as an imprint can be placed on the package/good at a predetermined application place very precisely even at high transport speeds, often with tolerances of a few hundredths of a millimeter. This high-precision movement or positioning of the transported goods is of crucial importance for quality when applying labels (printing barcodes, among other things) or in label detection (by scanner or camera), for example for purposes of quality assurance.
Forming the upper as well as the lower conveyor belt each from two conveyor bodies that are spaced apart side-by-side is also known. This arrangement of side-by-side conveyor bodies, each with a respective belt for example, allows the placement of or action by processing tools, for example printing heads, cameras, scanners, light gates, etc., even between the laterally spaced conveyor belts, in order to easily reach, for example, the bottom area of a package. Also, the laterally spaced belts prevent a rotation of the goods during transport. Another advantage lies in the fact that the goods can lie on the belts of the lower conveyor bodies distinctly spaced at their side edges, so that safety labels or seals can be applied on the side of the good without problem and can be shifted to the top or bottom side while the good is held between the upper and lower conveyor belts. Preferably, the processing takes place dynamically, thus while the goods are moving. Theoretically, a purely static processing is also conceivable, for which the goods can briefly be stopped. While the lower conveyor bodies are preassembled largely without a change in their height, the upper conveyor bodies are variably adjustable in height via a lift mechanism in order to be able to transport goods of different heights clamped between the upper and lower conveyor belts.